Various embodiments are directed to surgical instruments that may be used, for example, in open and minimally invasive surgical environments.
In various circumstances, a surgical instrument can be configured to apply energy to tissue in order to treat and/or destroy the tissue. In certain circumstances, a surgical instrument can comprise one or more electrodes which can be positioned against and/or positioned relative to the tissue such that electrical current can flow from one electrode, through the tissue, and to the other electrode. The surgical instrument can comprise an electrical input, a supply conductor electrically coupled with the electrodes, and/or a return conductor which can be configured to allow current to flow from the electrical input, through the supply conductor, through the electrodes and the tissue, and then through the return conductor to an electrical output, for example. Alternatively, the surgical instrument can comprise an electrical input, a supply conductor electrically coupled with the electrodes, and/or a return conductor which can be configured to allow current to flow from the electrical input, through the supply conductor, through the active electrode and the tissue, and to the return electrode through the return conductor to an electrical output. In various circumstances, heat can be generated by the current flowing through the tissue, wherein the heat can cause one or more haemostatic seals to form within the tissue and/or between tissues. Such embodiments may be particularly useful for sealing blood vessels, for example. The surgical instrument can also comprise a cutting member that can be moved relative to the tissue and the electrodes in order to transect the tissue.
By way of example, energy applied by a surgical instrument may be in the form of radio frequency (“RF”) energy. RF energy is a form of electrical energy that may be in the frequency range of 300 kilohertz (kHz) to 1 megahertz (MHz). In application, RF surgical instruments transmit low frequency radio waves through electrodes, which cause ionic agitation, or friction, in effect resistive heating, increasing the temperature of the tissue. Since a sharp boundary is created between the affected tissue and that surrounding it, surgeons can operate with a high level of precision and control, without much sacrifice to the adjacent normal tissue. The low operating temperatures of RF energy enables surgeons to remove, shrink or sculpt soft tissue while simultaneously sealing blood vessels. RF energy works particularly well on connective tissue, which is primarily comprised of collagen and shrinks when contacted by heat.
Further, in various open and laparoscopic surgeries, it is necessary to coagulate, seal or fuse tissues. One preferred means of tissue-sealing relies upon the application of electrical energy to captured tissue to cause thermal effects therein for sealing purposes. Various mono-polar and bi-polar RF jaw structures have been developed for such purposes. In general, the delivery of RF energy to a captured tissue volume elevates the tissue temperature and thereby at least partially denatures proteins in the tissue. Such proteins, including collagen, are denatured into a pertinacious amalgam that intermixes and fuses together as the proteins denature or form new cross links. As the treated region heals over time, this biological “weld” is reabsorbed by the body's wound healing process.
In a typical arrangement of a bi-polar radiofrequency (RF) jaw, the face of each jaw comprises an electrode. RF current flows across the captured tissue between electrodes in opposing jaws. Most commercially available bi-polar jaws provide a low tissue strength weld immediately post-treatment.
During some procedures, it is often necessary to access target tissue that requires severe manipulation of the end effector. In such applications, it would be desirable to have a curved and/or articulatable end effector arrangement to improve access and visualization of the surgical area by the surgeon.
The foregoing discussion is intended only to illustrate various aspects of the related art in the field of the invention at the time, and should not be taken as a disavowal of claim scope.